1. Field of the Invention
The present invention relates to a driving technique of a display, in particular, to a source driver and a driving method thereof.
2. Description of Related Art
In recent years, liquid crystal displays (LCDs) have become dominant in the market due to the advantages of low power consumption, zero radiation, and high space utilization. A source driver is a critical element in an LCD, which converts a digital signal into an analog signal for being used in displaying images, and transmits the analog signal to each pixel on a display panel.
Generally, an operational amplifier (OP) is disposed at an output stage of the source driver, thereby improving a driving capacity of the source driver. The OP has many specification parameters, such as a unity-gain frequency, phase margin, power consumption, common-mode rejection ratio, power-supply rejection ratio, input common mode range, slew rate, and noise. The slew rate refers to a change rate of an output voltage, which is generally defined as volt/second (or microsecond).
It should be noted that, the slew rate may affect an image quality of the LCD directly. The higher the slew rate is, the shorter the time required for the source driver to provide correct analog signals to a display panel will be. On the contrary, the lower the slew rate is, the longer the time required for the source driver to provide correct analog signals to the display panel will be. As a result, the lower slew rate may lead to blurring or flickering of images.